From 270ef8346ceadf03c1724db355f4ec06768e1f07 Mon Sep 17 00:00:00 2001
From: Jonathan Shimwell <mail@jshimwell.com>
Date: Wed, 22 Jun 2022 23:18:14 +0100
Subject: [PATCH] added metastable activity test

---
 tests/unit_tests/test_material.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tests/unit_tests/test_material.py b/tests/unit_tests/test_material.py
index c5d3276a0..c56c350b0 100644
--- a/tests/unit_tests/test_material.py
+++ b/tests/unit_tests/test_material.py
@@ -423,3 +423,11 @@ def test_activity_of_tritium():
     m1.volume = 1
     assert pytest.approx(m1.activity) == 3.559778e14 
 
+
+def test_activity_of_metastable():
+    """Checks that 1 mol of a Tc99_m1 nuclides has the correct activity"""
+    m1 = openmc.Material()
+    m1.add_nuclide("Tc99_m1", 1)
+    m1.set_density('g/cm3', 1)
+    m1.volume = 98.9
+    assert pytest.approx(m1.activity, rel=0.001) == 1.93e19